Apparatus for processing video signals and measuring the actual pulse width of these signals typically do not provide the results of the measurement in a form discernible to a human observer. For example, a method of detecting weld lines is disclosed in U.S. Pat. No. 4,305,096 issued Dec. 8, 1981 to Yokoshima et al. There, the video signal of the weld is compared with a reference threshold and binary coded into two signals, one representing a dark part and one representing a light part. These binary coded signals are then input to a computer for processing by a series of mathematical algorithms to determine various characteristics of the weld and to ultimately generate other signals for controlling the welding machine.
What would be advantageous and desirable is an apparatus and method for measuring the pulse width of such a video signal and displaying the results of the measurement in a form that is easily perceived by a human observer. Further the displayed indications should have a direct correspondence to a standard unit of measurement, or length, such as tenths of a micrometer.